The present invention relates to absorbent articles such as sanitary napkins, panty liners, adult incontinence devices, and the like which have side flaps. More particularly, the present invention concerns absorbent articles having side flaps that are provided with gathered portions that can expand to provide improved fit and coverage of the wearer""s undergarment when the flaps are wrapped around the side edges of a wearer""s undergarment.
All manner and variety of absorbent articles configured for the absorption of body fluids such as menses, urine, and feces are, of course, well known. Absorbent articles, particularly sanitary napkins, having wings or flaps are disclosed in the literature and are available in the marketplace.
Generally, the flaps extend laterally from a central absorbent means and are intended to be folded around the edges of the wearer""s panties in the crotch region. Thus, the flaps are disposed between the edges of the wearers panties in the crotch region and the wearer""s thighs. Commonly, the flaps are provided with an attachment means for affixing the flaps to the underside of the wearer""s panties.
The flaps serve at least two purposes. First, the flaps prevent exudates which otherwise would soil the edges of the wearer""s panties from doing such. Second, the flaps help stabilize the napkin from shifting out of place, especially when the flaps are affixed to the underside of the panties.
Sanitary napkins having flaps of the various types are disclosed in U.S. Pat. No. 4,687,478, entitled xe2x80x9cShaped Sanitary Napkin With Flapsxe2x80x9d, which issued to Van Tilburg on Aug. 18, 1987, U.S. Pat. No. 4,608,047, entitled xe2x80x9cSanitary Napkin Attachment Meansxe2x80x9d, which issued to Mattingly on Aug. 26, 1986, U.S. Pat. No. 4,589,876, entitled xe2x80x9cSanitary Napkinxe2x80x9d, which issued to Van Tilburg on May 20, 1986, U.S. Pat. No. 4,285,343, entitled xe2x80x9cSanitary Napkinxe2x80x9d, which issued to McNair on Aug. 25, 1981, U.S. Pat. No. 3,397,697, entitled xe2x80x9cDisposable Sanitary Shield For Undergarmentsxe2x80x9d, which issued to Rickard on Aug. 20, 1968, and U.S. Pat. No. 2,787,271, entitled xe2x80x9cSanitary Napkinxe2x80x9d, which issued to Clark on Apr. 2, 1957.
While sanitary napkins having flaps are commonly viewed as providing better protection against soiling as compared to sanitary napkins without flaps, the flapped napkins commonly experience problems that keep them from being optimally effective. These problems generally result from the stresses exerted on the flaps when the sanitary napkins are worn.
When the flaps are folded down along the edges of the wearer""s panties, stresses are created in the flaps, particularly when the flaps are relatively large in size. The stresses are especially high along the fold line at the edges of the wearer""s panties where the flaps are bent from the body side of the panty to the underside of the panty. These stresses are caused by fitting a flap around the curved edges of a panty crotch. The stresses are magnified when a wearer sits or crouches because the edges of the panties are pulled outward against the flaps thus increasing the forces against this fold line. When the stresses become too high, the flaps may become detached from the panty and some portion of the aforementioned benefits of the flaps may be lost. In addition, even if the stresses are not sufficient to detach the flaps, they may still be sufficient to cause the flaps to bunch longitudinally inward. This effectively reduces the size of the flaps and the area of the wearer""s undergarments that the flaps are able to cover. Thus, there is a commercial need for a way of eliminating or at least reducing the stresses that develop in the flaps when folded, so as to prevent them from becoming detached from the wearer""s panties and losing ability to cover a given area of the panties.
A number of variations on the types of flaps described above have been presented in an attempt to solve these problems. A sanitary napkin having flaps with stress relief means in the form of a notch or a slit is described in U.S. Pat. No. 4,917,697 which issued to Osborn, III, et al. on Apr. 17, 1990. Absorbent articles having flaps and zones of differential extensibility for relieving the stresses which develop in the flaps are disclosed in U.S. Pat. No. 5,344,416 issued to Niihara on Sep. 6, 1994, and U.S. Pat. No. 5,354,400 issued to Lavash, et al. on Oct. 11, 1994. Although these sanitary napkins work quite well, the search for sanitary napkins having improved flaps has continued.
Therefore, it is an object of the present invention to provide an absorbent article, such as a sanitary napkin, having flaps that provides the absorbent article with further improved means for relieving the stresses that develop in the flaps when they are folded down along the edges of the crotch of the wearer""s undergarments and affixed to the underside of the undergarments. It is another object of the present invention to provide such an absorbent article with flaps that do not lose their ability to cover a given area of the wearer""s undergarments during wear.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in conjunction with the accompanying drawings.
The present invention is directed to an absorbent article, such as a sanitary napkin, having flaps that are provided with gathered portions that can expand to relieve the stresses that develop in the flaps when the flaps are folded down around the edges of the crotch of the wearer""s undergarments.
The absorbent article comprises a main body portion having two spaced apart longitudinal edges and two spaced apart transverse edges, and a pair of flaps associated with said main body portion, one extending laterally outward beyond each longitudinal edge of the main body portion. The main body portion comprises a liquid pervious topsheet, a liquid impervious backsheet joined to the topsheet, and an absorbent core positioned between the topsheet and the backsheet. The main body portion has a first end region, a second end region, and a central region disposed between the first and second end regions. The absorbent article has a principal longitudinal centerline and a principal traverse centerline. The flaps have a proximal edge, a distal edge, and a flap transverse centerline that intersects the principal longitudinal centerline of the absorbent article.
The absorbent article is provided with a gathered portion positioned between the principal longitudinal centerline and the distal edge of the flaps. A restraint, which extends along at least part of the central region of the main body portion, restrains portions of the gathered portion from unfolding while allowing the ends of the gathered portion to unfold at locations disposed longitudinally away from said flap transverse centerline. In particularly preferred embodiments, the sanitary napkin also comprises one or more zones of differential extensibility. The zones of differential extensibility comprise material that has a greater range of extensibility outward than the points on the flaps that are located along the flap transverse centerline. The zones of differential extensibility are preferably disposed laterally outward from the gathered portions and longitudinally away from the flap transverse centerline. A novel releasable wrapper is also provided for enclosing and protecting the sanitary napkin prior to use.